Regulating means for elastic fluid turbines



Mauch 12,)1'940. A. D. SOMES 2,193,658

REGULATING MEANS FOR ELASTIC FLUID TURBINES Filed Aug. 24, 1938 f g-l- Inventor:

Arthur D. Somes is. Attorneg.

Patented Mar. 12, 1940 UNITED STATES REGULATI NG MEANS FOR ELASTIC FLUID TURBINES Arthur D. Somes, Marblehead, Mesa, assignor to General Electric Company, a corporation of New York Application August 24,

9 Claims.

from a plurality ofintermediate stages for in- ,5 dustrial purposes or to turbines with a plurality of intermediate stages to which fluid is sup-plied .from external sources. The first type of turbine .is known. as .extraction turbine? .and the last type as mixed pressure turbine. The invenll) tion is of special interest in connection with turbines wherein also the exhaust elasticfluid from i the turbine is utilized for industrial purposes although it is not necessarily limited thereto. These turbines are known as non-condensing extraction or mixed pressure turbines. Generally a part of a condensing turbine may be considered anon-condensing turbine. In such non-con densing turbines it is desirable to control the admission of elastic fluid to the turbine and the flow of elastic fluid from one extraction stage to thenext lower stage in response to' a condition-appurtenant to the elastic fluid flowing in the extraction conduits and in response to a condition appurtenant to the elastic fluid flowing from the exhaust conduit. The more usual ap plicati on isthat of controlling the admission of elastic fluid to the turbine and the flow of elastic fluid from one extraction stage to the next lower stage in terms of the extraction stage pressure and of the exhaust pressure. The flow of elastic fluid through the turbine is so controlled as tomaintain substantially constant the pressure in "the various extraction Stages as well as the exhaust pressure. The speed of the turbine is maintained constant by other means such as by the alternating current generato'r'connected to 'it and operating in parallel with other speed controlled generating equipment.

. It is an object of, this invention to provide an 40 improVedreguIating mechanism for an elastic fluidturbine of the above type by which the flow of elastic fluid. through the turbine :may be so controlled as to maintain substantially constant a condition such as the pressure of the elastic .fluid at the several extraction stages and the pressure of the exhaust from the turbine during varying conditions of demand for elastic fluid from such extraction stages or from the exhaust of the turbine. It isa further object of this invention to provide a governing mechanism of a simplified nature for. a multi-stage extraction turbine of the above type which may, readily be adapted for controlling a turbineof an 11. number of extraction stages for the purpose indicated above.

1938, Serial No. 226,563

(01. so -m) Fora consideration of what I believe to be novel and my invention, attention is directed to the following specification and the claims appended thereto taken in connection with the accompanying drawing.

In the drawing, Fig. l is a diagrammatic view partly in section of a multi-stage extractiontur- 'bine arrangement provided with a governing mechanismembodying my invention and Fig. 2 is a fragmentary view illustratingthe governing apparatus in a second condition of adjustment. The governing mechanism is shown diagrammatically without the provision of hydraulic operating motors and pilot control valves therefor.

The elastic fluid 1nulti-stage extraction turbine arrangement is shown in the form of a single turbine having a, casing Hliorming a succession of intermediate stages i l, l2 and afinal stage itconnected in series as regardsthe flow of elastic fluid therethrough and from which elastic fluid is extracted through the conduits M. and i5 and supplied through the exhaust conduit It for various industrial purposes. The turbine has an inlet conduit H for supplying a flow of elastic fluid to the turbine. The flow of elastic fluid through the turbine is controlled by inlet valve it and interstage valves i9 and 2B. In the present instance these valves have been indicated as being of the disc type, but it is understcod that any other known type of inlet and interstage valves may be used. The governing mechanism, according to this invention, serves to control the inlet and interstage valves so as to maintain substantially constant the pressure condition of the fluid extracted from any of the several intermediate stages and the pressure of the exhaust from the final -stage during changes in demand forelastic fluid from any of these stages. Thus, in a specific arrangement, the governing mechanism may maintain constant pressures of 400, 300, and 1.00 pounds in the intermediate stages H and I2 and final stage it respectively, during changes .in demand for extraction or exhaust fluid.

The governing mechanism includes a main lever 2 pivoted at iflto a stationary part 23. Valve 29 controlling the flow of elastic fluid to the final stage is of the turbine is connected by a link M to the main lever as at 25. Valve 2?! is adjusted. so as to maintain a constant pressure of elastic fluid in the exhaust conduit It by a pressure responsive device as, shown in this instance as a collapsible bellows arrangement, which communicates with ,the' exhaust chamber of the final stage by conduit 2?. The movable end of the pressure responsive device is connected as by a link 28 to the main lever 2! and actuates it in accordance with the pressure btaining in the exhaust chamber of the final stage I3 or in the exhaust conduit Hi. In order that the pressure in the extraction conduits l4 and i5 be not disturbed as valve 24 is adjusted, valves l8 and I9 are so connected to the main lever 2| as to be moved simultaneously with and in the same direction as valve 28 when the main lever is actuated. in response to varying conditions of pressure obtaining in the exhaust conduit I6. Valve 59 is pivotally connected by a link 29 at 30 to a first arm of a right angle bell crank 3| which in turn is pivoted to the main lever at a common point 32. The pivots 3E! and 32 of the bell crank 3| normally extend in parallel alignment with the main lever 2!, while the pivots 32 and 33 thereof extend in perpendicular alignment with respect to the main lever. The second arm of the bell crank is pivotally connected at 33 to a link 34 extending parallel to the main lever 2|, the other end of which is pivoted at 35 to the movable end of a pressure responsive device 36. The pressure responsive device 36 shown in this instance as a collapsible bellows arrangement communicates by a conduit 3'! with the extraction stage I2. The pivot point 35 is normally in perpendicular alignment with the pivot point 22 of the main lever 2|, the distance between the pivots 35 and 33 of the link 34 being equal to the distance between the pivot points and 32 of the lever 2|. The valve I8 is pivotally connected by a link 38 at 39 to a first arm of a second right angle bell crank 40 which in turn is pivotally supported as at 4| on the end of the first arm of the first bell crank 35. Normally, pivots 39 and 4| extend in parallel alignment with pivots 30 and 32, and hence also normally parallel to lever 2|. The second arm of the second bell crank, extending at right angles to the first arm, is pivotally connected by a link 42, extending parallel to the first arm of the first bell crank, to one arm of a two-arm lever 43 which in turn is pivotally mounted at the common point 32 to the main lever 2|. The other arm of the two-arm lever is pivotally connected as at 44 to a link 45 extending parallel with the main lever 2| and the link 34, the other end thereof being pivoted as at 46 to a pressure responsive device 41. This pressure re sponsive device, shown in this instance as a collapsible bellows arrangement, communicates as by conduit 43 with the extraction stage II of the tiu'bine. It is understood that the two-arm lever 43 extends parallel with the second arm of the second bell crank 40 and that the pivots thereof are normally perpendicularly aligned through the common point 32 with the main lever 2|. The link 45 is the same length as link 34, the pivots 44 and 46 thereof being normally in perpendicular alignment with respect to the pivot points 32 and 33 at the right end and pivot points 22 and 35 at the left end.

A speed governor device 50 driven by the shaft of the turbine is provided for protecting the turbine against excessive over-speed in which case the main lever 2| will be so actuated to move the valves l8, l9 and 2!] toward the closed position irrespective of the demands indicated by the pressure responsive devices 26, 36 or 47.

The operation of the governing mechanism will now be described. Assuming that the turbine is in operation with a normal predetermined constant pressure of elastic fluid obtaining in the intermediate stages II and 2 and that the demand for elastic fluid from the exhaust conduit I8 is increased so as to cause a drop in pressure in the last stage l3. This drop in pressure will be communicated to the pressure responsive device 26 causing the bellows thereof to collapse whereby the main lever 2| will be rotated about the pivot 22 in a counter-clockwise direction. The valve 20, directly connected to the main lever, will accordingly be moved toward a more opened position allowing an increased flow of operating fluid therethrough. Since the pressure conditions in the extraction stages H and 2 are at the redetermined nor mal value, the pressure responsive devices connected to the stages will remain inactive maintaining the movable pivots 35 and 46 in perpendicular alignment with the pivot 22 of the main lever. Accordingly, the pivots at the other ends of the parallel links 34 and 45 will be moved upwardly and maintained in perpendicular alignment with the common point 32 on the main lever. The right angle bell cranks will not be rotated about their respective pivots, but will be carried upwardly, the pivot points 30 and 39 on the ends of the horizontal arms thereof moving upwardly in horizontal alignment with the common point 32 on the main lever. Hence, the valves l8 and I9 connected to the pivot points 39 and 3|] of the bell cranks 40 and 4| respectively Will be moved upwardly in proportionate amounts and adjusted to a more opened position simultaneously with the valve 2!] so that the flow of elastic fluid therethrough will be increased just suiflcient to supply the additional demand from the conduit IS without affecting the resultant pressure in the intermediate stages. It is understood, of course, that the areas through the valves l8, I9 and 20 are proportioned to the density of the elastic fluid flowing through them.

Should the demand for exhaust fluid decrease and the condition of pressure in the final stage l3 increase, the reverse operation of the governor mechanism will take place in which the main lever 2| will be moved in a clockwise direction moving the valves |8, l9 and 20 toward a more closed position simultaneously in proportionate amounts so that the flow of elastic fluid therethrough will be decreased by the same amount sufficient to equalize the quantity supplied to the demand.

Assuming that the demand for exhaust fluid remains constant, but that the demand for fluid through the extraction conduit |5 should increase, causing the fluid pressure in the extraction stage I2 to decrease, the pressure responsive device 36 communicating therewith would collapse as illustrated more clearly in Fig. 2. The pivot point 35 and the link 34 would accordingly be moved longitudinally to the left and the bell crank 3| rotated in a clockwise direction about the common point 32. This rotation of the bell crank 3| causes the valve l9 to move upwardly to a more opened position while the setting of valve 28 will not be disturbed. Since the demand for elastic fluid from the extraction stage II has not changed, the pressure responsive device 41 connected thereto will retain the pivot point 46 stationary so that the two-arm lever 43 connected to the parallel link 45 will not be moved. Accordingly, the bell crank 40 will not be rotated, but will merely be carried upwardly since the supporting pivot 4| is moved upwardly by the rotation of the bell crank 3|. Hence, the

valve I8, connected to the bell crank 40, will be moved to a more opened position simultaneously with valve 65 and in a proportionate amount. In the event that the demand for elastic fluid from the extraction stage l2 should decrease, the reverse operation from that just described. will take place in which the bell crank 3| willbe rotated in a counter-clockwise direction carrying the bell crank 40 downwardly moving the valves is and i8 toward a more closed position of adjustment. 7

Now assuming that the pressure of elastic fluid in the stages l2 and 13 remains constant, but that the demand for elastic fluidfrom the conduit I should increase, causing the pressurein the extraction stage H to decrease, the pressure re sponsive device ll would then collapse moving the'pivot point 46 tothe left. Movement of the parallel link d longitudinally to the left would cause the two-arm lever 43 to rotate about the common point 32 on the main lever and in turn rotate the bell crank lil in a clockwise direction about the pivot point 4| moving the valve I8 upwardly to :a more opened position. Should the pressure in the extraction stage II increase, the reverse operation from that just described would take place in which the bell crank 40 would be rotated in a counter-clockwise direction moving the valve is toward a more closed positioned of adjustment.

Thus, it is seen that by the governing arrangement described all of the flow controlling valves ahead of the extraction conduit, the pressure in which is varied by changing demands for elastic fluid, are simultaneously adjusted in the same direction and in proportionate amounts to supply an additional amount of elastic fluid through those portions of the turbine preceding the extraction conduit in which the change in demand of the valves.

for elastic fluid occurs to satisfy the requirements I for that particular stage. The existing normal pressure condition of the elastic fluid in the intermediate stages or following stages, as the case may be, are not disturbed by this adjustment It is obvious that the governing system described may be easily adapted for controlling the extraction fluidpressure from an 71. number of stages by simply adding an 11. number ofIarrangements similar to that described forcontrolling the pressure of the extraction stage II.

I For example, to modify the system for con trolling a turbine having instead of two as shown,

three extraction stages, a right angle bell crank similar to as may be pivoted on the end of the horizontal arm of bell crank 40, as adjacent the pivot point 39, and connected to the valve controlling the fourth stage, which may be ahead of stage ll. The arms of this bell crank will normally extend parallel to the corresponding arms of bell crank All, and may be controlled bylinks corresponding to, and parallel with links 42 and #5 connected together by a two-arm lever, similar to lever 43, through the common pivot point 32. A pressure responsive device arranged similar to device ll and communicating with the fourth extraction stage may then control the adjustment of the valve for the fourth stage.

It is understood that the specific control arrangement shown in the drawing and described above is only exemplary. For example, for the sake of clarity, in the drawing I have illustrated the second bell crank 40 as being mounted upon a slight extension of the first arm of. the bell crank 3 i. It may be preferred to mount the bell crank ti! on some other point'of the bell crank 3|, for example, so that pivot points 4| and 30 coincide. Further, it may also be desired to connect valve 26 to the main lever 2| at the common pivot point 32 so that valve 2!] will be moved in identical amounts with valves l8 and I9 when the main lever 2! is rotated by the actuation of the pressure responsive device 26. The arrangement, of course, contemplates the provision of suitable adjusting means in connection with the operation of the respective valves to compensate for the difference in pressure and volume of the elastic fluid in the various stages.

While I have described the control system of my invention in connection with a turbine arrangement in which the plurality of extraction stages are combined within a single shell, it is obvious that the systemis equally well adapt able for use in connection with other turbine arrangements. For instance, each extraction stage, such as H, l2, and I3, referred to above, may consist of separate turbine units, each including an admission valve for controlling the flow of steam through that particular unit, all of the plurality of units being connected together on. a common drive shaft. Each turbine unit may exhaust to the next lower pressure turbine unit through a conduit to which the extraction conduit may be directly connected instead of to the turbine casings as described above. Nor is it necessary that the separate turbines be connected together on a common drive shaft since the separate turbines may be connected together by various forms of couplings well known to the art of either the mechanical or electrical-types.

The turbine described above may also be operated as a mixed pressure turbine, that is, instead of extracting elastic fluid through the extraction conduits Id and I5 and using such fluid for. external purposes, elastic fluid at pressures lower than the pressure existing in the inlet of the turbine may be supplied through the conduitsl l and to intermediate stages. Under these conditions the operation of the turbine and the governing mechanism is exactly the same as described above. An increased supply through the conduit l4 causes an increase in pressure. The effect of such increase in pressure and the movement of the governing mechanism is the same as the effect of an increase in pressure in such intermediate stage due to decreasing demand for extraction fluid in case the turbine is operated as an extraction turbine. Briefly, decrease in demand for extraction fluid has the same'efiect as increasing supply of fluid to an understood that the apparatus shown is only. illus trative and that the invention may be carried out by other means without departing from the spirit thereon What I claim as new and desire to secure by Letters Patent of the United States is:

1. The combination of an elastic fluid turbine arrangement having at least three sections connected for receiving elastic fluid in series, conduits for extracting elastic fluid from between said sections or for supplying fluid to the turbine, admission valves for regulating the flow of elastic fluid to each of said sections, a lever actuated in accordance with the elastic fluid pressure after said last turbine section, means operatively connecting all of said admission valves for simultaneous adjustment by said lever, in-- dividual means responsive to the pressure of elas tic fluid after each intermediate turbine section and means connecting each of said pressure responsive means through a common pivot on said lever for proportionately regulating the admission valves ahead of each of said individual pressure responsive means and independently of the valves following said individual pressure responsive means.

2. A governing mechanism for a non-condensing extraction or mixed pressure turbine for controlling such turbine in response to changes in demand for extraction fluid, said turbine having at least three intermediate extraction stages, said governing mechanism including a main lever pivoted at one end and actuated in response to variations in the exhaust pressure of the last stage of said turbine, valve means for controlling the flow of elastic fluid to said last stage connected to said lever, valves for controlling the flow of steam to intermediate extraction stages of said turbine, means operatively connecting said last mentioned valves to said main lever so that said last mentioned valves are moved simultaneously by movement of said main lever, means responsive to the pressure of elastic fluid in each of said extraction stages operatively associated with said last mentioned means for controlling the elastic fluid pressure in corresponding extraction stages independently of movement of said main lever.

3. A governing mechanism for multi-stage extraction or mixed pressure turbine arrangements for maintaining substantially constant the elastic fluid pressure in each of a plurality of extraction conduits and the exhaust conduit of said turbine comprising a lever, a first valve means for controlling the flow of elastic fluid to the last stage of said turbine connected to said lever, a second valve means for controlling the flow of elastic fluid through the first preceding extraction stage of said turbine, a second lever pivoted on said first lever connected to said second valve means, nth valve means for controlling the flow of elastic fluid to the nth preceding extraction stage of said turbine, an nth lever pivoted on the (n1)th lever and connected to said nth valve means, means responsive to pressure in said nth preceding extraction stage for adjusting only the nth lever and the valve associated therewith, means responsive to pressure in said first preceding extraction stage for adjusting only the second to the nth, inclusive, levers and the valves associated therewith and means responsive to the exhaust pressure of said turbine for adjusting said first, and a second to the nth, inclusive, levers and the associated valves.

4. A governing mechanism for multi-stage extraction or mixed pressure turbine arrangements for maintaining substantially constant the elastic fluid pressure in each of a plurality of extrac tion conduits and the exhaust conduit of said turbine comprising a lever, valve means for controlling the flow of elastic fluid to the last stage of said tiubine connected to said lever, a second lever pivoted on said first lever, valve means for controlling the flow of elastic fluid to the first preceding extraction stage of said turbine con nected to said second lever, a third lever pivoted on said second lever, valve means for controlling the flow of elastic fluid to the second preceding extraction stage of said turbine connected to said third lever, means responsive to pressurein said second preceding extraction stage for adjusting only the third lever and the valve associated therewith, means responsive to pressure in said first preceding extraction stage for adjusting only the second and third levers and the valves associated therewith and means responsive to the exhaust pressure of said turbine for adjusting said first, second and third levers and the associated valves.

5. A governing mechanism for multi-stage extraction and mixed pressure turbine arrangements for controlling such turbine arrangements in response to changes in demand for extraction fluid, said governing mechanism including a main lever pivoted at one end and actuated in accordance with the exhaust pressure of the last stage of a turbine, a first valve for controlling the flow of elastic fluid to said last stage connected to said main lever, a second valve for controlling the flow of elastic fluid to the first extraction stage preceding said last stage, said second valve connected to one arm of a right angle bell crank pivotally supported at a common point on said main lever, said one arm normally extending parallel to said main lever, a link parallel with said main lever and pivoted at one end to said second arm of said bell crank in perpendicular alignment With said common pivot point, said link pivoted at the other end in perpendicular alignment with the pivot point of said main lever, said link being longitudinally movable by a device responsive to the exhaust pressure of said last mentioned last stage, a third valve for controlling the flow of elastic fluid to the second stage preceding said last stage, said third valve being connected to a first arm of a second right angle bell crank pivotally supported on the end of the bell crank arm connected to the valve controlling the flow of elastic fluid to the first preceding extraction stage, the corresponding arms of said bell cranks being normally parallel, a second link parallel with said main lever and said first mentioned link and pivoted in alignment with the pivots of said first link and the pivot points on said main lever, said second link pivotally supported at one end to said common point on said main lever by a second lever parallel with said second arm of said first mentioned bell crank, said second lever connected to the second arm of said second bell crank by a member parallel to the first arm of said second bell crank, said second link being longitudinally movable by a device responsive to the pressure of the exhaust of said second preceding stage.

6. A governing mechanism for multi-stage extraction and mixed pressure turbine arrangements for controlling such turbine arrangements in response to changes in demand for extraction fluid, said governing mechanism including a main lever pivoted at one end and actuated in accordance with the exhaust pressure of the last stage of a turbine, valve means for controlling the flow of elastic fluid to said last stage connected to said main lever, valve means for controlling the flow of elastic fluid to the first preceding extraction stage of said turbine, said last mentioned valve means connected to one arm of a right angle bell crank pivotally supported at a common point on said main lever, said one arm normally extending parallel to said main lever, a link parallel with said main lever and pivoted at one end to a second arm of said bell crank in perpendicular alignment with said common pivot point, said link pivoted at the other end in perpendicular alignment with the pivot point of said main lever,

said link being longitudinally movable by a device responsive to the pressure of said first preceding extraction stage, means for Controlling the flow of elastic fluid to the nth extraction stage preceding saidlast stage including valve means connected to one arm of an nth right angle bell crank pivotally, supported on the end of the bell crank arm connected to the valve controlling the flow of elastic fluid to the (nl)tli stage, the" corresponding arms of said bell cranks being nor-' mally parallel, an nth link parallel with said main lever and'said first mentioned link and pivoted in alignment with the pivots of said first mentioned link and the pivot points on said main lever, said nth link pivotall'y supported at one end to said common-point ofsaid main lever by an nth lever parallel with said second arm of said first mentioned bell crank, said nth lever connected to the second arm of said nth bell crank by a member parallel to the first arm of said nth bell crank, said nth being longitudinally movable by a device responsive to extraction pressureof said nth extraction stage.

'7. A governing mechanism-for anon-condensing elastic fluid turbine having at least two intermediate extraction or mixed pressure stages and valves for regulating the flow of elastic fluid from one extraction stage to the next succeeding stage and controlling extraction fluid and exhaust fluid pressure, a' first means responsive to the extraction fluid pressure of one intermediate stage, an adjustable support, a first right angle bell crank pivoted on'said support and having a first arm connectedto said pressure responsive means and a second arm operatively connected to the valve for said one extraction stage, a second means responsive to the extraction fiuid pressure of the preceding extraction stage, a second right angle bell crank pivoted on said second arm of said first bell crank having a first arm connected to said second pressure responsive means and a second arm'normally parallel with the corresponding arm of said first bell crank and operatively connected to the valve for said precedingextraction stage, the connection between said sec-H ond fluid pressure responsive means and said second lever being such that movement of said first fluid pressure responsive means actuates both valves simultaneously and in the same direction and said second fluid pressure responsive means actuates only said second valve, a valve for the last turbine stage connected to said support, and

means responsive to turbine exhaust pressure for adjusting said support.

8. Governing apparatus for a multi-stage extraction and mixed pressure turbine having interstage valves for regulating extraction fluid pressure of each of a plurality of intermediateextraction stages, a first pivoted right angle bell crank having first and second arms, a first actuating means responsive to extraction fluid pressure after said first valve connected to said first arm,

the second arm being connected to a first inter-- stage valve, a second right angle bell crank hav-. ing first and second arms, said second bell crank being pivotally supported on the second arm of said first bell crank, said second arm oi said second bell crank being connected to a second interstage valve preceding said first inter-stage valve, a second actuating means responsive to extraction fluid pressure between said first and second valves connected to the first arm of said second bell crank, the corresponding arms of said bell cranks normally extending parallel with each other, said actuating means being connected to said bell crank arms by links extendingparallel to each other and tosaid second arms, said links being pivotally connected to saidactuating means at points perpendicular to said second arms and in alignment with thepoint of pivotal support of said first bell crank.

eratively connected to the valve for said one extraction stage, a second device responsive to the extraction fluid pressure of the preceding extraction stage, a second right angle bell crank pivoted onthe second arm of said first lever, said -second bell crank having a first arm connected .to said second pressure responsive device and a second arm operatively connected to the valve for said preceding extraction stage, said second device being connected to said second lever through said common point whereby actuation of said first device eflects movement of said valves in like amounts and in the same direction and movement of said second device effects actuation only of said second valve.

' ARTHUR D. SOMES. 

